The latest Investing Matters Podcast episode featuring Jeremy Skillington, CEO of Poolbeg Pharma has just been released. Listen here.
AB,
"So what we're saying here is that the Tumour has shrunk by 90%?"
No. You have missed the point entirely. The medical assessment of tumour changes are:
Progressive
Stable
Partial response
Complete response.
Percentages are applied to these using the area of the tumour before and after.
Hypothetically, a perfectly spherical tumour that has reduced from 4 to 1.8 has reduced 80% by area. This makes sense to me - see my previous post.
This reduction (80%) is described medically as "partial response" since the next level (complete response) only applies when the tumour has disappeared.
Whether anyone would get excited about an 80% reduction is a matter for the individual. If it was me with the tumour I would!
Botski,
"there's obviously a reason that tumour size is measured in cm and not cm2 or cm3."
It is measured in centimetres as this is the easiest to measure from a scan. However, the assessment of change is calculated in area using two dimensions (centimetres squared).
This makes sense as I would think the tumour expands on the surface where it will have access to blood vessels for the oxygen and nutrients it needs for growth.
I did the calculation using the surface area of a sphere and the reduction (4 to 1.8 diameter) is 80%
If only tumours grew as perfect spheres we wouldn't have an issue!
WTP,
"... mentioned on the other forum RE reduction percentages. Talk of approximately 90% reduction."
You need look no further than this forum - the 90% reduction was posted by moonparty yesterday (17:05). This is the reduction in volume. The reduction in area is 80%. Area is used to report tumour shrinkage and determine category - partial response, stable, progressive. A 90% reduction in volume is classed as a "partial response". Rather understated imo.
Moonparty,
"I hope those with better knowledge than I can educate as as to what is the correct measurement when trials talk about percentage reductions."
"WHO criteria
Tumour size is determined by measurement of the ‘tumour area’ by multiplication of the largest diameter of the tumour by the greatest perpendicular diameter"
So the way I interpret that would be if the tumour is a perfect sphere with a 4cm diameter, the "tumour area" is 4x4=16. The reduced tumour is 1.8x1.8 = 3.24 which is 20% of 16. Reduction in area is therefore 80%(which falls in the "partial response" category)
So although trials talk about reduction in area rather than volume, it is still phenomenal.
Ratty,
"Says a lot"
Perhaps it does in your paranoid mind? Actually, I was going to reply. To your 16:55 but moonparty had made the same observation. But as you are manic that all parts of the spectrum are represented, here's what I was going to say:
Ratty,
I don't think you will find many tumours in the shape of a straight line. So comparing a 4cm one with one that is 1.8cm (55% difference) is not a realistic comparison. We should be comparing a disc, a sphere or possibly a cylinder. If we compare the volume of a sphere with a 4cm diameter with one of 1.8cm, the difference is 90%. Even using a 2d disc, the difference is 80%.
Essential maths when working out the best pizza deal!
Bermuda,
Sorry, they were both SCIB1. I found the 2014 one in an RNS and didn't check the 2015 one. Of course it would have been SCIB as well. As you say, the detail is not important - my question was about the significance of 2015 and you answered with it was the last time Scancell have presented at AACR/ASCO.
So how long term is the £8 prediction - 2045?
I think there is a big difference doing "thorough research" on the science and concluding "hey, this could work" and doing a thorough analysis of the potential financial rewards.
Cleaner,
Yes, very interesting and pertinent to Scancell.
Reminds me of the capability maturity model. I'd thought that Scancell were pretty immature but that was based on their journey towards providing a financial return. However, the nature of the business dictates that strict processes and controls are in place.
Interesting comment from J-M
"We had a tendency to develop products because we could do it and not because they were wanted in the market,”
So possibly concentrate on The Moditope platform and sell the rest off?
Then look for better commercial opportunities elsewhere?
Wigwammer,
"Can we agree the positive DTH data has a positive impact on the chance of success?"
I don't see why not. A positive DTH response surely improves the chance of success. It is important to remember that a DTH response in itself ISNT a success as it isn't one of the primary outcome measures.
I think the updates are fine too. Scancell can only report facts. I think the frustration exhibited by some is the content of the news. Unfortunately, Scancell can only report what has happened and not what some would like to have happened or speculate as to the significance of certain facts. For example, the DTH - this is NOT one of the primary outcome measures. It seems TD have taken account of this along with the "partial response" in one patient, and upped the success chance percentage accordingly (from 10% to 12.5%). Although this has only added a few pence to the SP forecast, any increase is welcome.
Thanks Chester.
I'm not sure whether a correlation will be looked for or indeed found. LD said it "could" be measured not that would be. DTH response is not listed as an outcome measure in the clinical trial submission.
As you say, a fascinating few months ahead. .
Enjoy the footy!
So when we at school we used to have a TB test - a twelve needle gun in the forearm to check for existing immunity to TB. The reaction presumably is a DTH response?
This was merely observed by the nurse to decide who would and wouldn't get a TB jab. There was no measuring involved as I recall (but it was a long time ago)
I'm guessing that any observed reaction (swelling) is a good indication of a positive response but the actual measure is not a criteria for assessing efficacy.